Traditional blockchain design gives miners or validators full control over transaction ordering, i.e.,~they can freely choose which transactions to include or exclude, as well as in which order. While not an issue initially, the emergence of decentralized finance has introduced new transaction order dependencies allowing parties in control of the ordering to make a profit by front-running others' transactions. In this work, we present the Decentralized Clock Network, a new approach for achieving fair transaction ordering. Users submit their transactions to the network's clocks, which run an agreement protocol that provides each transaction with a timestamp of receipt which is then used to define the transactions' order. By separating agreement from ordering, our protocol is efficient and has a simpler design compared to other available solutions. Moreover, our protocol brings to the blockchain world the paradigm of asynchronous fallback, where the algorithm operates with stronger fairness guarantees during periods of synchronous use, switching to an asynchronous mode only during times of increased network delay.

翻译：传统区块链设计赋予矿工或验证者完全掌控交易排序的权力，即他们可以自由选择包含或排除哪些交易，以及交易的顺序。尽管最初这不是问题，但去中心化金融的出现引入了新的交易顺序依赖性，使得掌握排序权的一方能够通过抢先他人交易获利。本研究提出分布式时钟网络，这是一种实现公平交易排序的新方法。用户将交易提交至网络的时钟节点，这些节点运行共识协议为每笔交易生成接收时间戳，并据此确定交易顺序。通过将共识与排序分离，本协议相比现有方案更高效且设计更简洁。此外，本协议将异步回退范式引入区块链领域：在同步使用期间，算法以更强的公平性保证运行；仅在网络延迟增大时才切换至异步模式。